A Demon in Beacon
by djs1998
Summary: What if when Rin was born he was sent to remnant in order to stay safe and with Glynda Goodwitch as his mother but just how safe will the son of Satan be in a school to fight monster
1. Rin goes to Remnant

**Deep in a forest**

In a cave in a forest you see to men standing in front of a woman with two infant children in her arms, one has blue flames covering him is Rin while another is a sickly pale is Yukio and the woman is dead. Then a tall old looking man with glasses with crosses on the strings black robes and a sword whose name is Shiro Fujimoto steps forward while unsheathing and raising the sword and says, "Now it is time to kill the son of Satan!". But then something happened that he didn't expect the boy with the flames smiled at him. This caused him to stop and say, "He smiled at me the one with the flames I am about to kill him and he smiled at me". He lowers the sword and tells his friend, "I can't bring myself to kill a child but I can't him either what should we do Mephisto?".

His friend Mephisto Pheles a tall man with almost purple hair, green eyes and almost dressed like a weird looking clown says to him, "I have an idea but I will only use it on the one with the flames he could be trouble if his demonic powers awaken here but first ine sphine drine" and suddenly the flames on Rin go straight into the sword Kurikara also known as The Koma Sword a demon slaying sword. "There that way he won't be flaming up so sealed his demonic heart in The Koma Sword, now for part two of my plan I am going to take the boy to another dimension that is neither Ascia or Gehenna, but an entirely different one called Remnant to someone who owes me a favor she will raise the child."

"Are you sure about this?" Shiro asks.

"Oh certainly it will definitely be better than here now I will be taking the boy and The Koma Sword with me incase he might need his powers he can use them." Mephisto says he grabs the boy and the sword. "Now then ine sphine drine." and in a puff of smoke the just disappear.

 **The World of Remnant the City of Vale**

In the city of remnant at the house of one Glynda Goodwitch a tall blond haired woman wearing a white blouse, black skirt and pants, heels and a cape holding her weapon a riding crop to help with her semblance telecanieus Mephisto shows up and knocks on her door she opens up and immediately scowls at him and then sees the baby and the sword and raises an eyebrow and asks, "What's with the kid and the sword?"

He tells her, "oh nothing just here because you owe me a favor and now it is time to pay up because I want you to be this boy's mother."

A look of surprise can be seen on her face as she yells, "WHAT?! I am not qualified to be a mother and yet you expect me to raise him and you still haven't told me what the sword is for?" She yells and also wake up little Rin which cause her motherly instincts to kick in and grab him and start rocking him and lulling him back to sleep.

"Well you what do you know you are qualified to be a mother." He says and she takes her eyes of Rin to scowl at him. "Well the reason for the sword is because this boy is no ordinary boy he is the son of Satan and this sword which is called Kurikara aka The Koma Sword a demon slaying sword contains his demonic heart and powers if he ever draws the sword he can never again be human.", he tells her and she couldn't help but feel sad for the boy. "So that is why i bring him to you if he is here than he won't have to worry about exorcist trying to kill here he is safer then he would be at Ascia but just to warn you demons and possibly even Satan himself will come after young Rin here so be careful.", he warns her.

"Alright I will take care of him and I will make sure he is safe", she says as she takes the sword and hides it away.

"Very good now then I shall leave you with enough supplies to take care of the boy for at least two weeks after that you will have to get the supplies ine sphine drine", he tells her and then poof baby supplies just suddenly appears in the living room "Now then your debt has been payed good luck taking care of Rin and here is my number if you need help with him controlling his demonic powers", he says as he hands her a piece of paper with his number and then disappears in a puff of smoke leaving Glynda alone with Rin.

"Rin huh that's a nice well Rin it looks like it is just you and me and no matter what I will always love you my son demon or not", she says she kisses his forehead and she takes him into her bedroom and they both go to sleep for the night.


	2. Rin gets new friends

**Chapter 2**

 **Summer will still be alive because she doesn't go on the mission because she was watching Rin for Glynda**

 **6 years later**

Rin Goodwitch is now 6 years old and is in first grade and is seen walking through the halls all alone especially after last weeks fiasco when Rin got so angry he lost control and beat the snot out of a kid for calling him a demon his mother was a little mad but was more worried about him losing control and after that they had a talk about learning to control his emotions. As Rin is walking through the halls he sees the local bully Cardin Winchester and his group bullying a faunus girl a year older than the with bunny ears on her head an Australian accent and long brown hair. They were pulling her ears and saying, "Oh man I wonder if they are real?"

This angers Rin to no extent that he just charges Cardin head on and tackles him to the ground as the girl falls on her butt and starts beating him up and his goon squad yelling, "You leave her alone you bastard you shouldn't be picking on her for something she can't control!" he throws Cardin and his goons across the halls with punch to their stomachs. "Now you leave her alone or else next time I see you you will be in even more pain." he threatens, with a glare that could match his mother's they run off screaming like little girls. Rin then calms down and walks over to the girl they were bullying and sticks his hand out and she flinches.

"Please don't hurt me or pull my ears" she says, still scared that she might get hurt.

"Don't worry i'm not gonna hurt you my name is Rin Goodwitch it's nice to meet you what's yours?" he asks with a smile in a kind way.

"My name is Velvet, Velvet Scarlatina it's nice to meet you too" she says as she accepts his hand they shake hands and he helps her up then they hear the principal coming and Rin yells.

"Ah crap i'm dead my mom is gonna kill me for this!" as the principal drags Rin and Velvet to his office and when they get there they wait in there until their mothers come and needles to say Glynda was pissed as well as Velvet's mother when they got there.

"Thank you for coming here on such short notice ladies I am sorry about this but i have gotten reports that Rin and Velvet beat up Cardin and his friends" the principal said and the mothers were shocked until Rin yelled

"That is not true Cardin and his group were bullying Velvet I stepped in because i was tired of them picking on her and i was the only one fighting not Velvet so leave her out of this you got that now leave her alone!" he all but yells at the principal and gets right in his face.

The principal gets in his face and yells, "You wanna say that again kid?!"

Rin yells in a slow angry voice, "Leave… Her… Alone" as the small wood furnace explodes and little blue flames appear and disappear from the explosion everyone but Rin jumped back in shock. Glynda goes to put a hand on him to calm him down but someone else beat her to it. Rin feels a hand on top of his he looks to his right to see it is Velvet's hand on top of his and he calms down a little and Rin just sits back down.

"Well since Rin has admitted to beating up Cardin he shall be suspended from school for six weeks for this that is all dismissed" the principals says a little frightened from what just happened. As they left the office Rin was stopped by Velvet and she says to him.

"Thanks for what you did back there that was really nice of you" to which he says.

"No problem what are friends for" as he said that you could see a smile on Glynda's face so they both departed with a smile and a wave goodbye.

When Glynda and Rin get home Rin was expecting his mother to yell at him but she did something he did not expect she hugged him and says, "I am so proud of you my little boy and the man you are becoming you did something that made me so happy. You stood up for someone when no one else would I am so proud of you." she says as she lets go but then says, "but that doesn't mean you're off the hook three weeks with no tv young man"

Rin would be mad but then again he did deserve it for what he did "alright mom."

She smiled and gave him a big old kiss "Now go on and go outside to play and I will call your Aunt Summer to bring Ruby and Yang over when they get out of school ok?"

"Ok mom I love you"

"I love you too son now go on and play" and after that thing went of without a problem when the girls came over Glynda went to where she stored Kurikara and saw that there was a little smoke rising from it and soot on the seal and she saw that the seal was burnt a bit. She grew worried that the seal will disappear soon and his powers will awaken soon and that he will be in danger from demons and from Satan himself.

 **3 weeks later**

We now see Glynda and Rin in a market shopping for food for the week on there way to another store they see a white fang protest and people throwing stones at them. This made Rin pissed, and he got even more pissed when he saw a young girl with black hair and cat ears get hit in the head and started to bleed. He ran right up to the faunus protesters much to Glynda's worry and tried to act as a shield and yells, "leave them alone!" when they didn't listen and continue to throw rocks with some hitting him he gets even more angry " Leave… Them… Alone!" he yells even louder and the stones in their hands burst into blue flames along with the stones already thrown and they all disintegrated into nothing with his anger reaching its boiling point and charges them but is stopped by his mother and is pulled back to her but only to her only for to whisper something in his ear.

"You can scare them with a good display of your strength" he smiles deviously at that idea and went over to a concrete divider which shattered completely and everyone ran screaming run it's a demon while Rin just walked up to his mother and takes his shirt off.

Glynda raises an eyebrow until he rips his shirt in half and grabs a water bottle out of the many bags they have and walks up to the cat faunus and says, "Hold still this might sting a little." as he soaks his shirt to disinfect the wound and clean up the blood and she flinches because of the pain. Rin then takes the other half of his shirt and ties it around her head where the wound is and says, "There that should do it your wound will take sometime to heal but that should keep it disinfected oh by the way my name is Rin Goodwitch it's nice to meet you what's your's" he asks as he sticks his hand out to her, which she accepts and says.

"Blake Belladonna nice to meet you too and thanks for what you did back there for us but why did you do that no human has ever done anything like that for us"

"Well why wouldn't I it wouldn't be right to just stand by while people hurt other people who just want equal rights and it shouldn't matter if you don't look like the rest of us you're still human outside appearances don't matter it's what's on the inside that matters I can tell you're all good people you just want what you deserve, so I understand what you're doing." he stopped and thought for a minute until he had an idea he walked up to his mother and whispered his idea into her ear, "Hey mom is it okay if we cook some food for these guys while they protest?" she thought about before she nodded. He turned to them and asked do you guys have a grill or something to cook with?" one of them nodded and brought it forward along with some cooking utensils. Rin did the one thing he is good at he cooked them an amazing meal that they all loved.

Then Blake walked up to Rin and says, "Thank you for that meal it was really nice of you and you are an amazing cook by the way but why cook all of this for us you didn't have to?"

"Thanks cooking is one of the only thing I know how to well and I know but hey what are friends for anyways besides i couldn't let you guys go hungry while me and my mom eat food it wouldn't feel right." he says and the talk for a while until his mother calls.

"Rin it's time to go home now."

"Aw but mom I am talking to my friend."

"You can see each other later we have to go now or is it you don't want to leave your girlfriend" she teased. At that remark Rin and Blake both blush like mad crazy and Rin yells.

"Moooom."

"Come along now Rin and say goodbye to Blake oh and Blake you are welcome over anytime ok."

"Ok thank you Miss. Goodwitch."

"Please Blake call me Glynda and your welcome."

"Normally this would be the part where is say goodbye but i'm not gonna because I hate goodbyes so instead I will say i'll catch you later" Rin says as he smiles and waves at Blake and she smiles and waves back as Rin runs up to his mother and helps her carry the groceries home. Leaving Blake to wonder.

' _Why does he hate goodbyes?'_


	3. Rin's Demon powers awaken

Chapter 3

 **9 years later**

It has been 9 years since Rin's demonic power flared up and Glynda has grown worried, she is worried that she might have to tell Rin the truth, she is also worried about how he will react towards her keep his powers a secret since he is unable to have his aura unlocked and she thinks it is because of his demonic powers. But things are starting to change for Rin since he turned 15. He has grown quite smart while at school he had thought about dropping out but decided against it so he wouldn't suffer his mother's wrath. He is also able to hold down a job right now he is working at Tucson bookstore and has done a good job there and he has been a lot happier especially when he will occasionally run into Blake whether it is at work or out on the streets and they usually end up having tea together when Rin is not working they have grown quite close with each other, Rin still hangs out with Velvet but he spends a lot of time with Blake. Speaking of growing close Rin has also grown close with Ruby and Yang that they are practically like sisters to him. He has even forged his own weapons dual wielding swords that turn into pistols and he isn't half bad with them all in all Glynda's worries have gone down slightly but not a lot. But who knew that today would be the day that everything changes.

Right now Rin is pinned to the ground because of Cardin's thugs decide to sneak attack him while Cardin is walking to him with a piece of hot metal and this all started be cause rin decided to beat up Cardin two days ago because he was bullying Velvet. As Cardin is getting closer to him Rin is yelling, "Get away, just leave me alone" but Cardin just keeps on coming and finally Rin has had enough and he gets angry and shouts, "I… Said… Get… Away!" as Rin suddenly blue flames burst from Rin's body and Cardin and his thug are sent flying and they run from seeing Rin covered in flames. Rin is in so much shock that he does the only thing he can think of find his mother and tell her what happened.

Glynda is right now at home reading a book enjoying the nice Saturday that she is having. She was about to turn the page when Rin barges through the door and slams it behind him shocking her by the sudden action but she immediately became worried when she sees Rin in a panicked state and asks, "Rin what's wrong why do you looked panicked?" and with his next words she grew even more worried.

"I suddenly just had blue flames burst from my body" and those words nearly made her heart stop. "What's going on with me how did that happen and why did that happen I am so freaked out by this?!" he was about to start to hyperventilate until Glynda grabs him pulls him into a comforting hug to calm him down a bit.

She then tells him, "I can explain everything son but first you need to follow me" Rin does as he is told and when she let's go he follows her to her room as he sit on her bed she goes to her closet she pulls out something hidden behind her clothes and shoes that Rin doesn't understand what it is but a look of worry appears on his mother's face. She turns to him and says, "This sword is known as Kurikara or The Koma Sword it is a demon slaying sword and this rightfully belongs to you" she says as she hands him the sword. "But before you think about drawing it I need to tell you something" as a look of sadness appears on her face. "Rin you are the son of Satan and you are not even from this dimension" she says shocking Rin completely and she tells him the whole story of how he came to her and that the blue flame are a sign to anyone even in this dimension that it is a sign of Satan and if he draws the sword he will awaken his powers but will never be human again. "I have been meaning to tell you this for a while but I was just so scared of what you might say if you found out" she says as tears form in her eyes and she starts to cry. "I was so scared that you might hate me if I told you this and that you might leave if I told you about your origins, i am so sorry for keeping this hidden from you all this time and for lying about your father please…" but that is as far as she got before Rin grabs her and pulls her into a hug and says to her.

"It's ok mom i understand why you did it you did it to protect me and I understand and I could never hate you, you're my mother you raised me since I was an infant and gave me all the love and attention I needed while growing up so please don't ask me to forgive you I could never hate for trying to protect me all I have to say is thank you for being the best mom in the world for protecting me from getting hurt you're the best mom in the world" he tells her and she slowly stops crying on his shoulder. "But you have been lying to me and you always told me lying is bad" he says and she starts to get worried and thinks that he is going to hit her only sweat drop at his next statement. "So for your punishment you have to tell me how to make that awesome lasagna of yours please"

She sighs and says to him, "Fine I will teach you how to make my lasagna" to which Rin does a little yes but puts his hand up to stop her and then he says.

"No I said you will "tell" me how to cook it for it is my punishment to make dinner for tonight because I made you cry on your birthday mom" she sighed but nodded her head. "Oh and I almost forgot" he says as he runs out and runs back with a box wrapped in purple wrapping paper. "Happy Birthday mom and I love you mom." Rin says and she just wraps him in a hug and with that the night went by smoothly.

 **The Next Day**

Rin has gotten up early today to make his mother breakfast in bed. When he had finished making it he carried the food into her room to see that she is still asleep he puts the food on her night stand and wakes her up. "Hey mom time to get up." she opens her eyes and looks to see Rin sitting on her bed.

"Morning Rin what are you doing in here" she asks as she sits up.

"Well as a way to say sorry for making you cry last night I decided to make breakfast in bed for you" he says as he sets a tray full of eggs, bacon, toast and orange juice for her. All of a sudden the doorbell rings and they both adopt a look of confusion and look at each other confused. "I'll get the door while you enjoy your breakfast."

"No it's alright i'll come with you I want to find out who it is too." she says as she gets up and puts her bathrobe on over her nightgown. They both go to the and Rin has The Koma Sword and open the door only to see a man with his head down then he starts to laugh.

"Hahahahaha I have finally found you" then he suddenly burst into blue flames. Both Glynda and Rin take a step back.

"Y-your Satan" Rin says

"That's right but if you want you can call me papa hahahahaha" he says as the body he is possessing starts to bleed from everywhere. "Now then it's time to go" he says as he moves to grab Rin's arm.

"Stay away from us!" he says as he bursts into blue flames too and steps in front of his mother in a defensive position but Satan just laughs.

"Hahahahaha did you just piss your pants" he says as breaks his arm and it starts to bleed and it spills on the floor and it starts to form something.

"What is that?" Rin and Glynda asks at the sametime.

"Gehenna Gate." he says. As the gate starts forming and they hear laughing. Satan then grabs Rin's wrist and throw him into Gehenna Gate only for Glynda to in turn use her semblance to throw a knife in his back and for him to fall into Gehenna Gate and slowly die. "Once Gehenna gate has a hold of you it will never let go." as he says that Glynda uses her semblance to try to get him out but she fails.

"Ahh I got get out of here" he says as he notices that The Koma Sword is not getting sucked in. He then got an idea and reaches for the hilt of the sword and Glynda yells.

"What are doing if you draw that sword you'll never be human again?"

""I know and I don't care!" he says as he draws the sword and his powers are unleashed and he sprouts a tail, his ears become pointed and grows fangs and blue flames cover him. He raises his sword and slams it down on the sword on the gate and destroys it. When the gate vanishes he resheathed his sword and the flames go away and his ears become less pointy. Glynda runs over to him and grabs him in a hug.

"I am so happy that you're safe but why I could have got you out?" she says.

"Yes but if this power can help me protect the people I care for then so be it I would have do it again besides I couldn't risk him hurting you once he threw me into the gate I couldn't let him hurt my mother."

"I guess I should have seen that coming you are my son anyways." after that they spent the rest of the day trying to figure out a perfect idea for Rin's powers and features.


	4. meeting old friends and secrets are told

Chapter 4

 **2 years later**

It has been two years since Rin has drawn The Koma Sword and awakened his demonic powers and since then him and his mother have come up with away to hide his tail and to explain his fnag and ears. Rin is now 17 and is now on his way to Beacon he is standing with his 'sister' Yang and surprisingly his other 'sister' Ruby even though she two years younger than them and is also on a Bullhead to Beacon.

"Oh I can't believe my baby sister is going to Beacon with me this is the best day ever." Yang says as she squeezes Ruby in a tight hug.

"Me too it's so good to see you here and that you're going to Beacon with us it is so good to have you here we are going to have so much fun." Rin says as he gives Ruby a hug too.

"Please stop." Ruby says as Yang let's her go but Rin still holds on.

"But why we are going to have so much fun together and i'll love having my little sister here with me while my other sister is here too." Rin says as Ruby returns the hug and then they let go.

"Okay Rin I happy about that we can hang out like old times" Ruby says all excited and they start talking about the old times and Rin really starts to think about how much he has changed and he looks at himself and he sees how he look and sees that he now has three swords strapped to his side, a white jacket, blue jeans, black shirt, black combat boots and black gloves, and gun holster on the side of his chest (basically how he looked in the first episode of the show but with you know the obvious changes).

All of sudden Rin hears, "I guess the view isn't for everyone" Rin looks around and notices how far they gotten and how long he was zoned out for. They then see a blond scraggly looking kid walking by trying not to vomit and then Yang shouting ew for some reason. The ship then docks at the school and everyone steps out. The blond puking guy ran to a trash can and starts vomiting so Rin walks over to him and starts to pat his back.

"It will all be ok man you're motion sickness will pass you'll feel better soon." he said patting his back.

"Thanks man i'm Jaune Arc what's your name?"

"Rin Goodwitch nice to meet you"

"Nice to meet you too and wait did you say Goodwitch as in the Headmistress of Beacon Academy"

"Yeah she's my mom and she's just the best well when she is not in teacher mode that is."

"Well that's cool" all of a sudden they hear an explosion go off and run to see what's going on. When they get there they hear.

"The same company known for their cruel labor force treatment and questionable business practices" and Rin immediately recognized the voice.

They see a white haired girl scoff and walk off and Ruby standing saying sorry to the white haired girl another girl with black hair and a bow as about to walk away until grabs her and hugs her from behind. "Hey Blake it has been a while I have missed you" Rin says and Blake's eyes widen as he lets go she turns around to see Rin standing there. She then proceeds to grab him and pull him into her own hug.

"Rin it is so good to see you I have missed you too it has been a while"

"It's good to see you too man you've changed since the last time I saw you hmm let me see you have definitely have gotten more beautiful since the last time I saw you" Rin Flirts with her while acting foolish which makes Blake blushes but giggles at the goofy six year old he can be. They are about to start talking again until they hear a 'uhum' and turn to see Ruby and Jaune standing there. "Oh where are my manners Blake I would like to introduce my little sister Ruby Rose and my new friend Jaune Arc guy this my old friend Blake Belladonna".

Ruby and Jaune say hi to Blake while she says "it is nice to meet you and I finally get to meet Rin's infamous little sister "wielder of the dreaded puppy dog eyes" Rin calls you" which both Blake and Ruby giggle at Rin's child like behavior and Blake giggles even more when Rin grabs Ruby and pulls her into a nuggy. They then go to the amphitheater and find Yang and Rin introduce her to Blake only for her to tease.

"So Rin this is your girlfriend you have talking about?" to which Blake and Rin blush at and Rin delivers an elbow to Yang's face for embarrassing them.

"Shut up Yang oh and that was for trying to embarrass Blake." Rin says to which Blake blushes again because Rin would elbow Yang in the face for her.

"What you don't want to be Blake's boyfriend?" Yang teased to which Rin blushed and so did Blake and Rin was backed into a corner and Blake also had a curious look on her face at what Rin's answer would be.

"W-w-well I uh we're uh" Rin stutters out. Blake grabs his hand and gives it a comforting squeeze and a nod of her head with a smile, silently saying she would be fine with whatever answer he gave Yang. He was about to answer when Ozpin came up to the mic and gave a speech. 'Man that was close I want to tell Blake but not in front of Yang I don't need her embarrassing me.' after Ozpin's speech Glynda told everyone where they would be staying but thanks to Rin hearing this for a few years he already knows where to go so in order to tell Blake he grabs her hand and they sneak out unnoticed by everyone but Glynda but let's it slide with a slight smile on her face.

 **Courtyard in front of the school**

"Rin what are you doing we need to know where we are staying?" Blake questions

"Don't worry I know where we have to go but I wanted to ask you something." Rin says and Blake raises an eyebrow but allows him to continue. "Well Blake I wanted to ask you would you once the initiation is over would you like to go on a date with me?" Rin says as Blake blushes like crazy but is able to calm herself.

"I would love to once the initiation is over" she says

"Awesome but there something I want to show you so I won't regret not telling and so I won't hurt you by hiding this" Rin says and Blake raises her eyebrow again and Rin draws The Koma Sword and his blue flames come out and his tail, his ears are pointed again and his fangs sharpen Blake has a look of surprise. "I am the son of Satan, so what do you think of me now" he asks nervously as he puts his sword away only for Blake to hug him.

"You are still the man I fell for besides who your father is doesn't really matter you are not like your father and also I saw some blue flames destroy the rocks of the people who were throwing them at us when you stopped them when we were kids" she says as she plants a little kiss on his cheek. Rin blushes a bit but gets it under control and puts his tail away. "So where do go for the night to rest until the initiation?"

Rin snaps out of it and says, "Oh yeah follow me". They both head to the ballroom and find Yang and Ruby hanging out together they walk over their hand slightly touching each other and they smile at each other when they get to them Yang notice how they have changed.

"So you two have changed and where did you two go did you have a makeout session?" Yang teased which somewhat affected them but not really. "Wait what happened to you two?" before they could say anything the white haired girl came stomping up and yelling and Blake and Rin used that to duck out and go to a wall to sleep next to each other.

"Hey Rin is it okay if sleep next to you guys tonight?" Ruby asks.

"Sure thing Rubes come and snuggle up next to your big brother" Rin says as he scooches over and Ruby snuggles up next to him as Blake does the same. They rest up for the night to prepare for the initiation.

 **I plan on having Rin know all the fatal versus and have them work on the grimm since they are like demon and Rin is smarter than usual Rin sometimes**


End file.
